Barbara J. Maschak-Carey

Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes

BACKGROUND Weight loss is recommended for overweight or obese patients with type 2 diabetes on the basis of short-term studies, but long-term effects on cardiovascular disease remain unknown. We examined whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among such patients. METHODS In 16 study centers in the United States, we randomly assigned 5145 overweight or obese patients with type 2 diabetes to participate in an intensive lifestyle intervention that promoted weight loss through decreased caloric intake and increased physical activity (intervention group) or to receive diabetes support and education (control group). The primary outcome was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for angina during a maximum follow-up of 13.5 years. RESULTS The trial was stopped early on the basis of a futility analysis when the median follow-up was 9.6 years. Weight loss was greater in the intervention group than in the control group throughout the study (8.6% vs. 0.7% at 1 year; 6.0% vs. 3.5% at study end). The intensive lifestyle intervention also produced greater reductions in glycated hemoglobin and greater initial improvements in fitness and all cardiovascular risk factors, except for low-density-lipoprotein cholesterol levels. The primary outcome occurred in 403 patients in the intervention group and in 418 in the control group (1.83 and 1.92 events per 100 person-years, respectively; hazard ratio in the intervention group, 0.95; 95% confidence interval, 0.83 to 1.09; P=0.51). CONCLUSIONS An intensive lifestyle intervention focusing on weight loss did not reduce the rate of cardiovascular events in overweight or obese adults with type 2 diabetes. (Funded by the National Institutes of Health and others; Look AHEAD ClinicalTrials.gov number, NCT00017953.).

Reduction in weight and cardiovascular disease risk factors in individuals with type 2 diabetes: one-year results of the look AHEAD trial.

OBJECTIVE—The effectiveness of intentional weight loss in reducing cardiovascular disease (CVD) events in type 2 diabetes is unknown. This report describes 1-year changes in CVD risk factors in a trial designed to examine the long-term effects of an intensive lifestyle intervention on the incidence of major CVD events. RESEARCH DESIGN AND METHODS—This study consisted of a multicentered, randomized, controlled trial of 5,145 individuals with type 2 diabetes, aged 45–74 years, with BMI >25 kg/m2 (>27 kg/m2 if taking insulin). An intensive lifestyle intervention (ILI) involving group and individual meetings to achieve and maintain weight loss through decreased caloric intake and increased physical activity was compared with a diabetes support and education (DSE) condition. RESULTS—Participants assigned to ILI lost an average 8.6% of their initial weight vs. 0.7% in DSE group (P < 0.001). Mean fitness increased in ILI by 20.9 vs. 5.8% in DSE (P < 0.001). A greater proportion of ILI participants had reductions in diabetes, hypertension, and lipid-lowering medicines. Mean A1C dropped from 7.3 to 6.6% in ILI (P < 0.001) vs. from 7.3 to 7.2% in DSE. Systolic and diastolic pressure, triglycerides, HDL cholesterol, and urine albumin-to-creatinine ratio improved significantly more in ILI than DSE participants (all P < 0.01). CONCLUSIONS—At 1 year, ILI resulted in clinically significant weight loss in people with type 2 diabetes. This was associated with improved diabetes control and CVD risk factors and reduced medicine use in ILI versus DSE. Continued intervention and follow-up will determine whether these changes are maintained and will reduce CVD risk.

Long-term effects of a lifestyle intervention on weight and cardiovascular risk factors in individuals with type 2 diabetes mellitus: Four-year results of the look AHEAD trial

BACKGROUND Lifestyle interventions produce short-term improvements in glycemia and cardiovascular disease (CVD) risk factors in individuals with type 2 diabetes mellitus, but no long-term data are available. We examined the effects of lifestyle intervention on changes in weight, fitness, and CVD risk factors during a 4-year study. METHODS The Look AHEAD (Action for Health in Diabetes) trial is a multicenter randomized clinical trial comparing the effects of an intensive lifestyle intervention (ILI) and diabetes support and education (DSE; the control group) on the incidence of major CVD events in 5145 overweight or obese individuals (59.5% female; mean age, 58.7 years) with type 2 diabetes mellitus. More than 93% of participants provided outcomes data at each annual assessment. RESULTS Averaged across 4 years, ILI participants had a greater percentage of weight loss than DSE participants (-6.15% vs -0.88%; P < .001) and greater improvements in treadmill fitness (12.74% vs 1.96%; P < .001), hemoglobin A(1c) level (-0.36% vs -0.09%; P < .001), systolic (-5.33 vs -2.97 mm Hg; P < .001) and diastolic (-2.92 vs -2.48 mm Hg; P = .01) blood pressure, and levels of high-density lipoprotein cholesterol (3.67 vs 1.97 mg/dL; P < .001) and triglycerides (-25.56 vs -19.75 mg/dL; P < .001). Reductions in low-density lipoprotein cholesterol levels were greater in DSE than ILI participants (-11.27 vs -12.84 mg/dL; P = .009) owing to greater use of medications to lower lipid levels in the DSE group. At 4 years, ILI participants maintained greater improvements than DSE participants in weight, fitness, hemoglobin A(1c) levels, systolic blood pressure, and high-density lipoprotein cholesterol levels. CONCLUSIONS Intensive lifestyle intervention can produce sustained weight loss and improvements in fitness, glycemic control, and CVD risk factors in individuals with type 2 diabetes. Whether these differences in risk factors translate to reduction in CVD events will ultimately be addressed by the Look AHEAD trial. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00017953.

Erectile Dysfunction in Type 2 Diabetic Men: Relationship to Exercise Fitness and Cardiovascular Risk Factors in the Look AHEAD Trial

INTRODUCTION Determinants of erectile dysfunction in diabetic men have not been adequately investigated as potential mediators of change. AIM To determine the prevalence and correlates of erectile dysfunction (ED) in overweight men with type 2 diabetes in the multicenter, Look AHEAD trial (Action for Health in Diabetes). MAIN OUTCOME MEASURES International Index of Erectile Function (IIEF), self-reported use of phosphodiesterase type 5 inhibitors, laboratory measures of adiposity, cardiometabolic parameters, and exercise fitness. METHODS Male participants aged 45-75 in the Look AHEAD trial in a committed relationship were recruited for an ongoing study of sexual function and diabetes. Eligible participants completed the IIEF questionnaire and provided updated information on use of medical treatments for sexual dysfunction. Baseline sexual function results for participants in the male ancillary study are reported here; intervention data and results for female participants are presented elsewhere. RESULTS A total of 373 eligible male participants completed all sexual function questionnaires, of whom 263 (68.7%) were sexually active at the time of the study. Almost half (49.8%) of the men reported mild or moderate degrees of ED, and 24.8% had complete ED. Among sexually active participants, 42.6% had sought medical help for their problem, and 39.7% reported use of ED medications. ED was significantly associated with age (odds ratio [OR] = 1.05; confidence interval [CI]: 1.01-1.10) baseline HbA(1c) (OR = 1.31; CI: 1.05-1.63), hypertension history (OR = 2.41; CI: 1.34-4.36), and metabolic syndrome (OR = 3.05, CI: 1.31-7.11). Of note, cardiorespiratory fitness was found to be protective of ED in a multivariable analysis (OR = 0.61; P < 0.001). CONCLUSIONS ED is prevalent in this sample of obese, type 2 diabetic men in the Look AHEAD study. Cardiovascular risk factors were highly associated with ED in this population, and cardiorespiratory fitness was protective in this analysis.

Brain and White Matter Hyperintensity Volumes After 10 Years of Random Assignment to Lifestyle Intervention

OBJECTIVE Type 2 diabetes increases the accumulation of brain white matter hyperintensities and loss of brain tissue. Behavioral interventions to promote weight loss through dietary changes and increased physical activity may delay these adverse consequences. We assessed whether participation in a successful 10-year lifestyle intervention was associated with better profiles of brain structure. RESEARCH DESIGN AND METHODS At enrollment in the Action for Health in Diabetes clinical trial, participants had type 2 diabetes, were overweight or obese, and were aged 45–76 years. They were randomly assigned to receive 10 years of lifestyle intervention, which included group and individual counseling, or to a control group receiving diabetes support and education through group sessions on diet, physical activity, and social support. Following this intervention, 319 participants from three sites underwent standardized structural brain magnetic resonance imaging and tests of cognitive function 10–12 years after randomization. RESULTS Total brain and hippocampus volumes were similar between intervention groups. The mean (SE) white matter hyperintensity volume was 28% lower among lifestyle intervention participants compared with those receiving diabetes support and education: 1.59 (1.11) vs. 2.21 (1.11) cc (P = 0.02). The mean ventricle volume was 9% lower: 28.93 (1.03) vs. 31.72 (1.03) cc (P = 0.04). Assignment to lifestyle intervention was not associated with consistent differences in cognitive function compared with diabetes support and education. CONCLUSIONS Long-term weight loss intervention may reduce the adverse impact of diabetes on brain structure. Determining whether this eventually delays cognitive decline and impairment requires further research.

Effect of a Long-Term Behavioral Weight Loss Intervention on Nephropathy in Overweight or Obese Adults with Type 2 Diabetes: the Look AHEAD Randomized Clinical Trial

BACKGROUND Long-term effects of behavioural weight loss interventions on diabetes complications are unknown. In a secondary analysis of the Look AHEAD (Action for Health in Diabetes) multicentre randomised clinical trial, we assessed whether an intensive lifestyle intervention (ILI) affects the development of nephropathy in people with type 2 diabetes. METHODS Overweight or obese people aged 45-76 years with type 2 diabetes were randomly assigned (1:1) to ILI or to a diabetes support and education (DSE) group by a central web-based data management system, stratified by clinical centre and blocked with random block sizes. The ILI was designed to achieve and maintain weight loss through reduced caloric consumption and increased physical activity. The interventions were terminated early because of absence of effect on the primary outcome of cardiovascular disease events in the main Look AHEAD trial. Albuminuria and estimated glomerular filtration rate were prespecified as two of many other outcomes and were assessed from baseline until the interventions ended. They were combined post hoc to define the main outcome for this report, very-high-risk chronic kidney disease (CKD), based on the 2013 Kidney Disease Improving Global Outcomes (KDIGO) classification. Outcomes assessors and laboratory staff were masked to treatment, but participants and interventionists were not masked. Time-to-event data were analysed by intention to treat by the Kaplan-Meier method and proportional hazards models. The Look AHEAD trial is registered with ClinicalTrials.gov, NCT00017953. FINDINGS Of the 5145 participants randomly assigned in the Look AHEAD trial (2570 to ILI and 2575 to DSE), analyses for very-high-risk CKD were done in 2423 (94%) of patients in the ILI group and 2408 (94%) of those in the DSE group. After a median of 8·0 years (IQR 7·9-9·9) of follow-up, the incidence of very-high-risk CKD was lower in the ILI group than in the DSE group, with incidence rates of 0·91 cases per 100 person-years in the DSE group and 0·63 per 100 person-years in the ILI group (difference 0·27 cases per 100 person-years, hazard ratio 0·69, 95% CI 0·55-0·87; p=0·0016). This effect was partly attributable to reductions in bodyweight, HbA1c, and systolic blood pressure. There were no safety concerns regarding kidney-related adverse events. INTERPRETATION Weight loss should be considered as an adjunct to medical treatments to prevent or delay progression of CKD in overweight or obese people with type 2 diabetes. FUNDING National Institute of Diabetes and Digestive and Kidney Diseases.

Effect of a long-term behavioural weight loss intervention on nephropathy in overweight or obese adults with type 2 diabetes

BACKGROUND Long-term effects of behavioural weight loss interventions on diabetes complications are unknown. In a secondary analysis of the Look AHEAD (Action for Health in Diabetes) multicentre randomised clinical trial, we assessed whether an intensive lifestyle intervention (ILI) affects the development of nephropathy in people with type 2 diabetes. METHODS Overweight or obese people aged 45-76 years with type 2 diabetes were randomly assigned (1:1) to ILI or to a diabetes support and education (DSE) group by a central web-based data management system, stratified by clinical centre and blocked with random block sizes. The ILI was designed to achieve and maintain weight loss through reduced caloric consumption and increased physical activity. The interventions were terminated early because of absence of effect on the primary outcome of cardiovascular disease events in the main Look AHEAD trial. Albuminuria and estimated glomerular filtration rate were prespecified as two of many other outcomes and were assessed from baseline until the interventions ended. They were combined post hoc to define the main outcome for this report, very-high-risk chronic kidney disease (CKD), based on the 2013 Kidney Disease Improving Global Outcomes (KDIGO) classification. Outcomes assessors and laboratory staff were masked to treatment, but participants and interventionists were not masked. Time-to-event data were analysed by intention to treat by the Kaplan-Meier method and proportional hazards models. The Look AHEAD trial is registered with ClinicalTrials.gov, NCT00017953. FINDINGS Of the 5145 participants randomly assigned in the Look AHEAD trial (2570 to ILI and 2575 to DSE), analyses for very-high-risk CKD were done in 2423 (94%) of patients in the ILI group and 2408 (94%) of those in the DSE group. After a median of 8·0 years (IQR 7·9-9·9) of follow-up, the incidence of very-high-risk CKD was lower in the ILI group than in the DSE group, with incidence rates of 0·91 cases per 100 person-years in the DSE group and 0·63 per 100 person-years in the ILI group (difference 0·27 cases per 100 person-years, hazard ratio 0·69, 95% CI 0·55-0·87; p=0·0016). This effect was partly attributable to reductions in bodyweight, HbA1c, and systolic blood pressure. There were no safety concerns regarding kidney-related adverse events. INTERPRETATION Weight loss should be considered as an adjunct to medical treatments to prevent or delay progression of CKD in overweight or obese people with type 2 diabetes. FUNDING National Institute of Diabetes and Digestive and Kidney Diseases.